Various antireflective (“AR”) polymer films have been described. AR films are often constructed of alternating high and low refractive index (“RI”) polymer layers of the correct optical thickness. With regards to visible light, this thickness is on the order of one-quarter of the wavelength of the light to be reflected. The human eye is most sensitive to light around 550 nm. Therefore it is desirable to design the low and high index coating thicknesses in a manner that minimizes the amount of reflected light in this optical range (e.g. 3% or lower).
In one assembly, a high refractive index (e.g. hardcoat) is applied to (an optionally primed) light transmissible substrate such as PET. A low refractive index layer is applied concurrently or sequentially to the high refractive index layer.
Alternatively, however, AR coatings can be prepared from a coating composition that separates or self-assembles into layers of differing refractive index. See for example U.S. Pat. Nos. 6,605,229 (Steiner et al.), 6,737,145 (Watanabe et al.), U.S. Pat. No. 7,125,926 (Satoh et al.) and US 2006/0074172 (Yang et al.).